Improvement in automatic feed for paper-machines



J. T. P. MacDONNELL. Automatic Feed for Paper-Machines.

No. 25,946. Patented May 27, 1879.

.Plan %m Secila/z y y.

?VIT/mases.- I I I UNITED STA ES PATENT OFFICE.

JOHN T. F. MAC DONNELL, OF HOLYOKE, MASSACHUSETTS.

MPROVEMENT IN AUTOMATIC FEED FOR PAPER MACHINES.

Specification forning part of Letters Patcnt No. 2141946, dated May 27,1879; application filed May 27, 1878.

To all whom it may concem:

Be it known that I, JOHN T. F. MAC DON- NELL, of Holyoke, in the countyot' Hanpden and State' of Massachusetts, have inven ted certainImprovements in Automatic Feed for Paper-Machines, of which thefollowing is a specification.

The object of my invention is to secure the -delivery of the pulp orstuff in a paper-machine of a uniform consistency, in order to insureauniform thickness of the paper produced and to this end the inventionconsists in a method and apparatus in which the varying specific gravityof the stuff is caused to control the admission of the water used toreduce it.

My invention is capable of application to going through all thepreliminary p'rocesses,

of reduction to pulp, reaches what is termed the stilit-chest, which isa large tank or receptacle containing agitators to keep the contents ofuniform consistency and prevent the .separation and settling of theheavier portion. From this stuff-chest the contents are pumped, by apump connected with the machine, into what is called the stuff-box, astream of pure water being allowed to flow into the box when desired,and dilute the stufi before it passes to the machine proper and to thewire cloth, where the water is removed and the pulp left in the sheetform.

It is obvious that with a given quantity of stufi' passing out in agiven time to the machine the paper resulting will vary in thickness asthe stufi pumped into the stuff -box from the stuff-chest is thicker orthinner in consistency.

In practice it would be impossible for the attendant to preserve auniform consisteney of stuff by his own observation and tests with suchaccuracy as to insure a uniform thickness ,it wrong, the flowing mixturehas been and is still going out to the machine, .and consequently thesheet rendered too thick or too thin, while he has been testing andbefore he can remedy the difficulty.

Various attempts have been made to control automatically the flow of thestuff from the stuff-box, such as the use of self-regulatin g Valves,&c., and thus to control the thickness of the sheet; but in practice theattempts have all resulted in failure.

In order to secure the desired result,`l avail myself of the varyingweight of the contents of. the suff-box due to the changes which occurin the specific gravity of the stut' according as it contains more orless pulp or water' in proportion to each other.

The stuff-box in ny invention is always full to a certain height, therequired amount passing from it to the machine, and the residue flowingback into the stuff-chest.

In practice we find that the specific gravity of the stuff or stock isgreater than that of the water used to dilute it, and, consequently,that the weightof the contents of the stuff-box, although remaining thesame in Volume, will be greater or less, according as the proportion ofwater therein is ncreased or diminished. In order to make use of thisfact, I nount the stuff-box on a scale-beam, or otherwise support it sothat it is niccly balanced when filled with stuff ot' the exactconsistency desired, and so arrange a water-supply pipe and other partsthat whenever the' material becomes too thin,

and consequently lighter, the counter-,weight will elevate the box andcause the flow of water to be dininished, while'at, the same time theinward fiow of stuff continues, so as to bring the contents of the boxto the proper consistency. If, on the other hand, the material in thestuff-box should becone too thick,

and so much heavier than if of the proper consistency, the box andcontents will overbalance the counter-weight and cause the flow of waterto be increased, and thus restore the proper consistency.

The accompanying drawings represent one form of apparatus which may beemployed for carrying out my invention.

A represents the stuff-box, provided on its sides with trunnions a,supported in the arms of a forked scale-beam, B, which is pivoted at thepoint c and provided with a slidi g weight, O, which is so adjusted asto counterbalance the weight of the box A and its contents when thelatter is of the desired consistency. .D represents the spout throughwhich the stufl' is discharged into the stuff-box A to dilute itscontents, the pipe E, in the present case, being arran ged directlybelow the stuffspout D, with its end in line with the side of the box A,so that the latter may traverse verticall y past its mouth.

During the proper operation of the machine the stuff or pulp isdischarged through the spout D in a continuous stream into the box A,and a continuous stream of water also discharged through the pipe E intothe box A to reduce or dilute the stock to a proper degree of fiuidity,the rcduced mass flowing under the partition d and up into the narrowspace between the partition d and the end of the stuff-box, from whichspace the proper quantity is allowed to flow out to the machine throughan opening controlled by a gate or gage, while any surplus over andabove the normal Volume of contents flows over the ends of the saidnarrow space and finds its way back to the stuff-chest.

The use of the partition is important and advantageous in that itinsures an even mixture of the water and stock, and that it securcs thedelivery of the stock of' constant cousistency from the box, althoughthat in the body of the box separated by the partition may have a slighttemporary variation.

It is to be understood that when the box and its contents are inequilibrium with the counterpoise i. e., where the stuf in the stuffboxis of just the right consistency-the adjustment of parts will be suchthat about onehalf of the full flow of the water-pipe E will enter thebox.

Whenever the contents of the box A become diluted beyond the extent(lesired the specific gravity and weight of the mass are lessened,

whereupon the weight 0, preponderating over' the weight of the box,causes the latter to ascend and diminish the inflow of water from thewater-pipe E, the flow of pulp meanwhile continuing. As the mass attainsthe proper consistency again the increased weight causes the box todescend, and the inflow of water will be increased. In like manner, ifthe stuff in the box becomes too thick, the resulting downward movementof the box will produce a larger inflow of water, thus dilutin g, andconsequently lightening, the contents of the box,

which will again rise to its normal height when the proper consistencyis attained.

In practice thebox is to be so accurately counterpoised that it will atonce be actuated by any change in the weight of its contents, andrespond so readily that any variation in the consistency of the stuffwill at once be corrected.

Thus it will'be seen the admission of the water and the consistency ofthe pulp are regulated automatically and With great nicety, and thestuff delivered from the box of a uniform consistency.

In the drawings the stuff-pipe D is represe'nted as discharging from asmall box or chamber, F, into which the stuff is pumped from thestuff-chest, it being thought preferable to pump the stuff into thisintermediate chamber F rather than directly iuto the stuffbox A. A

For the purpose of limitin g the vertical motiou of the stuf-box aslotted standard, c, is mounted at one side of the box to receive astop-pin f, on the latter, as shown.

It is obvious, ,as above stated, that the arrangement of' the detailsmay be modified to any extent desired, provided the principle ofoperation of the apparatus is not changed. Instead of having the upperedge of the box A arrauged to traverse up and down before the mouth ofthe water-pipe E, it may be connected in any suitable manncr with avalve arrangca to regulate the ,discharge from said 1 e. p i furtherobvious that instead of controlling the consistency by limiting the flowof water into the box, the same result may be accomplished bypermitting, and at the same time controlling,a flow of water out of thestufl`-box; but this plan is not considered a desirable one forpractical use.

While it is prcferred to employ the balanced box, to be moved byvariations in the specific gravity of the stuff, it is obvious that thebox may `be made stationary and a properly d. justed float mountedtherein and connected with a valve or other device for regulating theadmission of water to the stuff in which the float is mounted, so thatas the specific gravity of the stuif is reduced by an excessive dilutionthe float will sink deeper, and thereby diminish the flow of water, andtas the specific gravity is increased again the float will be buoyedhigher and caused to increase the flow of water.

It is also obvious that instead of balancing the 'stuff-box, a specialregulating-box may be introduced into the machine and balanced in thesame manner, for the purpose of controllin g the dilution of the stuff.

I do not confine myself to any particular form of stuff-box or to anyspecial device for controllin g the outflow of stuff from it, as myinvention is applicable to all the different arrangements in use forthose purposes.

I am aware that attempts have been made to regulate the thickness of theweb or sheet in a paper-machine by regulating the flow of stock thereto,the flow being reduced as the stuff increased.

I am also aware that an attempt has been made to secure the same endthrough the instrumentality of abalanced fiexible diaphragm,

over which the stock was cansed to flow in a thin stream, and upon whichthe stock accumulated to an increased extent as it became thicker, thediaphragm being connected with a gate to regulate the flow, and with aValve through which water was discharged into that portion of the stockwhich had passed beyond the diaphragm into a feeding-chambcr. Thisarrangement, besides requiring an expensive and complicated apparatus,and necessitatin g a constant return of a portion of the stock to thefeeding nechanism, was objectionable and inefficient, for the reasonthat it did not secure a uniforn consistency of the material, the waterbeing introduced, not into the thickened portion of the stock upon thediaphragm, but into the stock which had already passed the same, andwhich was of the proper consistency, the consequence of which was thatthe stock, as delivered to the machine, varied con stantly inconsistency, being first too thick and then too thin. Besides, it wasfound that the Variation in the flow, to compensate for variations inthe consistency, required a delicacy of adjustment which was in practiceimpracticable.

Now, my invention difi'ers from the above nethods in striking at thecause instead of the effect-that is to say, in. controlling theconsistency instead of the flow, and in supplying the water to andredncing that portion of the material which governs the flow, instead ofto a different portion which has already been tested.

lt is to be particularly noted that in the form of apparatus shown by methe quantity of material in the regulator remains unchanged, and thatthe change in densityand specific gravity regulates the action; that theflow and the consistency remain continuous and unchanged, and that thewater is added directly to the stock being weighed or tested.

Having thus described the nature of my invention, and one form of theapparatus which may be enployed, what l claim is- 1. An apparatus forcontrolling the consistency of paper stock, consisting of a balancedvertically-moving receiver, arranged so that the pulp passes through thesame, and a water-supply arranged to dischargc into the receiVer, and tobe controlled in its rate of discharge by the movement of the receiver,substantially as shown.

2. The combination of the receiver A, balancing devices B C, with astock-feedcr, F, and water-feeder E, both arranged to deliver into thereceiver, and the latter arranged to be controlled by the verticalmovement of the receiver.

3. In a feed-regulator for paper-machines, a balancedregulating-receiver, A, arranged to rise and fall past the mouth of awater-pipe, E, as and for the purpose described and shown.

4. In a ieed-regulator for paper-machines, a balanced regulating-receiver, A, provided with. a vertical partition, d, and a passagethereunder, said receiver being arranged to receive the stock on oneside of the partition, cause its passage thereunder, and then dischargeit upon the opposite side, as described and shown, whereby the stock isdelivered of a uniform consistency.

5. The herei'-described method of securin g a uniforn consistency of thestock or stuff while being fed to paper-machines, cosisting in theemployment of a fixed Volume of stock or stuff, in connection with acounter-balance, and causing Variations in the specific gravity of saidpulp to control the addition ot' water thereto, in the manner and bymeans substantially such as described and shown.

6. In a feed-regulating device for papermachines,the combination of abalanced Vertically-moving vessel of fixed capacity and a water-supplycontrolled by the movements of the balanced vessel, substantially asdescribed and shown.

7. The herein-described method of controlling the consistency of thestock in its passage to paper-machines, consisting in applying thespecific gravity of each part or portion of the stock to control theaddition of water to that particular part or portion, in the manner andby means substantially such as described and shown.

JOHN T. F. MAC DONNELL.

W'itnesses:

J. P. BUCKLAND,

EMMA L. JORDAN.

